## Creating Circle Graphs using Excel

### Mary Kay BacallaoColleges and Universities - Florida

#### Description

Students evaluate data from a circle graph that compares time spent on various activities. They use the computer to manipulate their own data as they compare, examine, create and evaluate data using circle graphs.

#### Objectives

The student uses computer applications to examine and evaluate data.

#### Materials

-Sample Budget (See Associated File)
-Time Sample (See Associated File)
-Assessment Rubric (See Associated File)
-Student/teacher computers with Excel
-Projection system
-A printer with paper

#### Preparations

1. Download the associated file and put it on a teacher computer with a projector and on the student workstations.
2. Make sure that the students will be able to print out their work.

#### Procedures

Prerequisite: The students should already know about the uses for pictographs, bar graphs, line graphs, and circle graphs.

SESSION 1
1. Gain attention by discussing with students: Every person has 24 hours in each day. How do you spend your day? What do you spend the most time doing? We all have the same amount of time; it is up to us how we use it. Today we are going to look at some time breakdowns and compare them using circle graphs.

2. Explain to students: In our first example, we are going to analyze a sample circle graph of a budget. Then we are going to analyze a sample circle graph of how a student might spend 24 hours. We will consider how we spend our time and create a circle graph to represent what we spend our time doing in an average day. We will analyze our information and compare it with a partner. We will find out how circle graphs are different from other types of graphs.

3. Review the types of graphs and discuss the appropriate uses of each: pictographs, bar graphs, line graphs, and circle graphs. Some examples for each type of graph include: Pictographs can be used for comparing amounts. Each picture on the graph represents a given number of items. Bar graphs use the spaces on a grid and can visually represent and compare quantities such as votes in an election. Line graphs use coordinate graphing to represent changes over time such as temperature. Circle graphs are based on fractions, each circle represents a whole and each piece of the pie is a percentage of that whole.

4. Discuss the value of the circle graph in comparison to the other types of graphs. What does the circle graph show that the other graphs do not? With circle graphs, we can see the big picture. In one circle, we can compare the parts in a whole. We can see the value of each section of the pie as it relates to the whole.

5. Explain that circle graphs can be used in budgets. If we create a circle graph that shows what we do with our money, we can see the big picture of where our money is going.

6. Open up the pages that you have downloaded from the associated file. A sample budget is the first sheet that you see, and it is labeled “Sample Budget” on the bottom tab. Explain to the students that each category of the budget is represented with a percent. Point out the color legend and show them how they can find the values on the chart that are entered into the budget on the left. Explain that the sample budget is based on monthly income and expenses. Allow the class to suggest changes to the budget and make them so that the students can see the result of the changes on the graph. In order to make a change, click on the cell (box) with the number (money) value and enter a new value, then press the enter key. Your class will be able to see the effect of the change on the circle graph.

7. You can point out that with every change, the total percent value of the budget always remains 100%. This is due to the fact that circle graphs are based on parts of a whole and one circle or 100% is the whole. Even if the values are extremely high numbers, there cannot be more than 100%.

8. Explain to the students that there is a formula next to the word “total” where all the total values are automatically calculated. This number changes with each cell change, but the total represents 100% of the monthly income.

9. Click on the second tab at the bottom of the spreadsheet called, “Time Sample.” Point out to the students that in this case, all the values must add up to 24 hours. The values are represented in hours, so if the students need less than an hour they can use decimals as values. Make some changes in the values as a class as they suggest. You can change the values by clicking on the cell and entering the new value. Then press the enter key. Discuss the changes that happen in the graph as changes are made in the numbers.

10. Create a class sample day and analyze the day.

SESSION 2
11. Click on the third tab at the bottom of the spreadsheet to show the students the Assessment Rubric (See Associated File) for checking their work.

12. Group the students in pairs. Have each of the students do a “save as” with the file and rename it with their own name.

13. Have the students click on the bottom tab that reads, “Time Sample.” Have the students take turns and enter data to describe their day. Remind them that all the values must add up to 24 hours. They may change the category names by clicking on the cell and typing the new name, but they will not be able to add new categories. Circulate and formatively assess students as they use the technology tools. Provide assistance for students who are experiencing difficulty and monitor accordingly.

14. When both students have completed and saved their graphs, they should print the graphs and compare their days with their partner.

SESSION 3
15. Have the students write an analysis of their day in reference to the graph they have created. Write this question on the board: Why do you think we used a circle graph to show this data? Instruct students to answer the question in their writing.

16. Have each student also write about the make-up of their day on the graph compared to their partner’s day.

17. Have the students write reflections and conclusions based on what they have learned.

18. As the students are working, check to make sure that they do not exceed 24 hours. Provide assistance as the students are working.

#### Assessments

1. Use the criteria on the Assessment Rubric on the third tab of the Excel spreadsheet in the associated file to determine mastery. The written analysis including the answer to the question, as well as the graph, should be assessed using the rubric in the file. This is a formative assessment. Students who do not show mastery need feedback, guidance and extra practice in analyzing and evaluating the data on computer graphs. The tool may also be used as a summative assessment.

2. Circulate and formatively assess students as they use the technology tools. Provide assistance for students who are experiencing difficulty and monitor accordingly.

#### Extensions

1. The students can begin with the Time Sample and then use the Sample Budget as an extension instead of as an example to introduce the concept.
2. The students can do the same activity using the Sample Budget.
3. The students can also create their own circle graphs with other types of data.